Definition
A sheet metal forming process in which a small conical depression is pressed into a rivet hole using heated dies, allowing the head of a flush rivet to sit level with the surface of the skin. The heat softens the metal locally so it can be shaped without cracking, which is necessary for harder alloys, magnesium, and thicker materials that would split if dimpled cold.
Plain English
Pressing a small cone-shaped dent around a rivet hole, with the dies heated up, so that a flush rivet sits flat against the skin. The heat lets the metal stretch into shape without cracking.
Context Anchor
Seen in aircraft sheet-metal repair and construction, especially when preparing skin panels for flush rivets or screws.
Derivation
‘Dimple’ comes from the everyday word for a small dent or depression. ‘Hot’ refers to the heated dies used in the process. The name describes exactly what happens: a dimple is formed while the metal is hot.
Why Pilots Care
Produces flush, low-drag surfaces on heat-sensitive skins while preventing cracks that could grow under flight loads and compromise structural integrity.
Intuition Check
Do not read “hot dimpling” as heat damage or a cosmetic dent. It is a controlled maintenance process used to shape metal around a fastener hole.
Example Sentence 1
The repair manual called for hot dimpling because the magnesium skin would crack if formed cold.
Example Sentence 2
Hot dimpling was used on the titanium leading-edge skin to ensure the fasteners sat flush without stressing the material.